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I have been trying for days to successfully get 2mb games to write and read with no luck. 1mb games seem to work just fine. I've been thinking it's an issue with my programmer, as it uses a 16bit adapter for writing to M27C160s, but my chips blabk check, write and verify just fine, but will not load. That's when I learned that the SNES has an 8bit bus and that I need to alter my method. I am using Muramasa PCB's and they say they are compatible with M27C160 with no rewiring, so is it something to do with my method of programming the IC? With 1mb games using M27C801s, it seems as simple as removing the header, loading the file, convert to binary, write and verify. I take it programming onto the M27C160 isn't as cut and dry? Is there a setting in my programmer software that will allow me to write to it in 8 but mode to get the SNES to read it correctly? Or do I have to alter hardware to properly program it? If anyone has experience with this and would like to help, I am more than willing to listen, learn, and show my gratitude to the person patient enough to teach me.

I'm using a GQ-4x4 with the latest software. It does give me a byte swap option which swaps the buffer hi-low byte. I have tried this option when writing but it didn't seem to make a difference. I would assume this would be used if I were using a donor PCB and didn't want to do as much rewiring (like using the swapbin option with Wasabi), but I may be wrong as I have never used donor boards, only new PCB's from Muramasa. My other options I have are to change the file offset and/or device offset, which I have zero knowledge of how to do properly, or a button that has no documentation anywhere in the help guide or software, which looks like 8<--->16 which appears to change the format of the offsets and the way the code is arranged (columns 0-F of 2 to columns of 4 with no labeling). I have tried to write to Eproms both ways with no luck. I have read posts on other forums of others having issues with using this adapter for programming 2mb Eproms, so I know I'm not the only person in this boat. I'm willing to try anything at this point. I have 20 chips I can use to try anything suggested. I also have a new programmer ordered and will try it once it gets here and see what happens.

I use GQ-4X4 myself and programming and using 27c160 works just as fine.Simply program the 27c160 like you normally would with ADP-054 and connect the EPROM properly on the SNES booard/adapter/whatsoever.

There's also various diagrams and schematics showing how to connect a 27c160 on the internet.

Therein lies the problem. If I were working with a donor board that had a MAD-1... The PCB's I am using are new ones from Muramasa. There is no spot for anything other than my PIC12F629 SuperCIC, my eprom, 1 6.3v aluminum cap, and 2 50v ceramic caps. These boards are designed to be used with 27C160 with zero rewiring of an Eprom. The LoRom/HiRom selector is on the PCB, as well. Here is a link for reference:

Posted - 03/23/2018 : 14:56:44 Show Profile Email Poster Edit Reply Reply with Quote Delete ReplyJust a quick update. I received another batch of m27c160 Eproms from another supplier today and tried my luck again. I took 3 different dumps of the same file from 3 different sources and tried to program my new Eproms. I have 20 IC's in total. I have tried different combinations of everything from changing around the J5 jumper between v3/v4 positions, trying different write speeds. I got the same results: blank check said blank, file wrote and verified successfully, but when put into my system, I get a black screen.

I tried to change the devices.txt file for m27c160. People have recommended changing the WVCC from 5.5v (default) to 6.2v. Chips would blank check ok, but then fail to write before even 1%. I also tried 6.5v setting and got write fails before 1% after good blank checks.

Looking at the datasheet for M27C160, it says VCC for writing should be 6.25v (within 0.25v) and VPP at 12.5v. 12.5v VPP is not supported, 12.7v is default and the closest supported VPP voltage. Every write I attempt a WVCC that is not at the default WVCC of 5.5v and WVPP 12.7v settings, it fails to write before 1%.

Last edited by IHeartEproms on Sun Mar 25, 2018 6:13 am, edited 1 time in total.

That what I have done. I made 2 socket boards, one for LoRom, one for HiRom, did continuity check on the boards as I soldered to make sure each solder point had continuity, and one final check after I'm all finished, and I get nothing. Tried 20 different M27C160s all with the same results.

My jumper settings are J1=pin 1 and 2 short (forM27C160), J2 jumpers not used on GQ-4x4, as there are no address pins on the programmer PCB for them to go to, and J5 I have tried writing in v3 and v4 modes with no change in results.

I will take a few more pics of some of the other boards I've done later today when I am up at my shop where I have all my equipment.

I did a continuity check on both boards as they were being made, with one final check after they were finished. I had my most experienced employee with a soldering iron do the solders on my 42DIP LoRom board just to make sure it wasn't something I did wrong. (We run a vape shop, not a game store lol) Both boards pass a continuity check and the SuperCIC's verify and work in my 32DIP LoRom socket board I made.

I wonder if my adapter isn't faulty. I get the same thing with M27C800 Eproms as well. Blank check is okay, write/verify is okay, but when put into either PCB, nothing. Tried 5 different ones with both LoRom and HiRom 1mb games, in both v3 and v4 modes on J5 jumper.

I am not the first person to have this issue from what I've seen from days of scouring the internet for possible fixes to the issue. MCUMall customer support is a joke, as they think I am either not inserting the adapter/Eprom properly or that my adapter pins are dirty... Both of which things I've shot down as I have always aligned the bottom pins on the adapter with the bottom slots of the zif socket on the programmer and my 42 pin eprom is aligned at the bottom of the 48 pin socket on the adapter. I've cleaned the pins several times and made sure all the connections were tight, ran voltage diagnostic and did a H/W test with a multimeter to ensure the pin slots on the zif socket were transferring voltage correctly. They don't have a H/W test mode for the adapter, though.

I ordered a Xeltek a few days ago. I'm hoping it does better than the GQ-4x4 with 42 pin 2mb Eproms, as it supports 48 pins natively with no adapter.

It's not your programmers fault but rather your jumpers (on the boards, not your programmer!). I don't tihnk you're supposed to bridge ALL 3. Either Left + Middle or Right + Middle pad. If Muramasa didn't provide a tutorial, contact him/her about it how to set the jumper properly.

Also your soldering (from what it looks like) as some shorts on the bottom side of the EPROM. If there isn't then it's just the picture.

I have contacted Muramasa but haven't got a response. It's been about a week or so ago. Those jumpers have 3 pads on LoRom, HiRom, and a row in the center for LoRom/HiRom. When I do a continuity test on the jumper, with all 3 points bridged, I get signal from the jumper to the pins that go into the console, but with only 2 of 3 jumpers soldered, I get no signal. I've followed the traces on the board from that LoRom/HiRom jumper. The points on the back of the PCB lead to points that pick up on the front of the board and lead to points on the bottom row of pins of the eprom and down to the cartridge pins. Signal carries between all points from the jumper to connector pins. I will try to reach out to Muramasa again and see if I get an answer.

I would be more than happy to send someone a couple of preprogrammed Eproms, as well as some blank ones and my socket boards, to see if it's my programmer or my PCB's... Along with a gift to show my appreciation for helping me to solve my problem.

Do you get a black screen? Or no video out? There’s a distinct differerence. No video means the CIC isn’t working, black screen means issue with roms. Hopefully your TV tells you, or you have you console’s CIC disabled.

_________________If you're gonna play the Game Boy, you gotta learn to play it right. -Kenny Rogers

I get video signal in, just a black screen. I can tell because when I have no CIC in the board, I get no video signal due to the circuit not being complete. When I put my cic back it the board, I get signal, but a black screen. My TV says "No Signal" on the screen when it has no A/V signal. The "No Signal" remains on screen without a CIC installed, with the CIC, the "no signal" message goes away and I get a solid black screen that faintly looks like lighter colored black bars scrolling diagonally across the screen. I tried the same with my tested and working DIP32 basic LoRom board, no CIC gives No Signal, CIC in and it boots up perfectly fine. Repeated the process with both LoRom and HiRom DIP42 basic boards and I get a black screen. So far I have tried 20 different M27C160 Eproms and 5 different M27C800 Eproms and get the same black screen.

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